#include <cmath>
#include <cstring>
#include <iostream>
#include <queue>

using namespace std;

const int N = 55;
int g[N][N];
int dist[N][N];
bool vis[N][N];

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

struct Node {
    int x;
    int y;
    int d;

    bool operator<(const Node& t) const {
        return d > t.d;
    }
};

int main() {
    int T;
    int r, c;

    cin >> T;
    for (int C = 1; C <= T; ++C) {
        cin >> r >> c;
        for (int i = 1; i <= r; ++i) {
            for (int j = 1; j <= c; ++j) {
                cin >> g[i][j];
            }
        }

        memset(dist, 0x3f, sizeof dist);
        memset(vis, 0, sizeof vis);

        priority_queue<Node> heap;

        for (int i = 1; i <= r; ++i) {
            heap.push({i, 1, g[i][1]});
            dist[i][1] = g[i][1];
            heap.push({i, c, g[i][c]});
            dist[i][c] = g[i][c];
        }

        for (int j = 2; j < c; ++j) {
            heap.push({1, j, g[1][j]});
            dist[1][j] = g[1][j];
            heap.push({r, j, g[r][j]});
            dist[r][j] = g[r][j];
        }

        int res = 0;
        while (!heap.empty()) {
            Node t = heap.top();
            heap.pop();

            if (vis[t.x][t.y]) {
                continue;
            }

            res += t.d - g[t.x][t.y];
            vis[t.x][t.y] = true;

            for (int i = 0; i < 4; ++i) {
                int x = t.x + dx[i];
                int y = t.y + dy[i];

                if (x > 0 && x <= r && y > 0 && y <= c) {
                    if (dist[x][y] > max(t.d, g[x][y])) {
                        dist[x][y] = max(t.d, g[x][y]);
                        heap.push({x, y, dist[x][y]});
                    }
                }
            }
        }
        cout << "Case #" << C << ": " << res << endl;
    }

    return 0;
}